1. A composition for enhancing the immune response to a saccharide antigen, comprising: (a) a saccharide antigen conjugated to a carrier, and (b) an α-glycosylceramide adjuvant, where the saccharide antigen is a bacterial capsular saccharide and the carrier is a protein. The composition of claim 1, wherein the α-glycosylceramide adjuvant is α-galactosylceramide. The composition of claim 2, wherein the α-galactosylceramide is (2S, 3S, 4R) -1-O- (α-D-galactopyranosyl) -2- (N-hexacosanoylamino) -1,3,4-octadecantriol. . The composition of claim 1, wherein the bacterial capsular saccharide is obtained from Neisseria meningitidis, Haemophilus influenzae, or Streptococcus pneumoniae. A composition according to claim 1, containing more than one saccharide conjugate. The composition of claim 1, wherein the carrier is a bacterial toxin, such as diphtheria toxoid or tetanus toxoid. Carrier-conjugated saccharide antigen and an α-glycosylceramide adjuvant, where the saccharide antigen is a bacterial capsular saccharide and the carrier is a protein for use in medicine. 8. The saccharide antigen according to claim 7, wherein the saccharide antigen elicits an immune response in a patient. The saccharide antigen of claim 8, wherein the saccharide antigen conjugate and the α-glycosylceramide adjuvant are administered simultaneously, sequentially or separately. The saccharide antigen according to claim 9, wherein the immune response is intended to prevent and / or treat a disease caused by Neisseria (e.g., meningitis, septicemia, gonorrhea, etc.), H. influenzae (e.g., otitis media, bronchitis, pneumonia, cellulitis , pericarditis, meningitis, etc.) or pneumococcus (e.g., meningitis, sepsis, pneumonia, etc.). 11. Saha�1. Композиция для усиления иммунного ответа на сахаридный антиген, содержащая: (а) сахаридный антиген, конъюгированный с носителем, и (b) α-гликозилцерамидный адъювант, где сахаридный антиген представляет собой бактериальный капсульный сахарид, и носитель представляет соб
